Alyxian, Canticle of The Cave

Scales of Sorrow. The Canticle of The Cave starts combat with 100 temporary hit points. While any of these hit points remain the creature has resistance to all damage except Force damage and has a Damage Threshold of 20. When the Canticle of the Cave loses these Temporary Hit Points it become Mythic.

Titanic Trampling. If the Canticle of The Cave moves through a creatures space during his turn that creature must make a dexterity saving throw or take 3d10 Bludgeoning Damage, half damage for a save.

Cavernous Canticle. Any creature that is not Swallowed by the Canticle of The Cave and starts its turn within 15ft of the Canticle must make a DC 21 Wisdom Saving Throw or become Confused until the start of its next turn as haunting music echoes through the caverns where the Canticle makes its home. A Confused Creature must roll 1d8 to see what they can do with their turn.
1-2: Creature is Stunned until the start of their next turn.
3-4: The creature can Move, Take a Bonus Action, Take the Dodge Action, OR Take the attack action (one attack only) on their turn and may not cast spells.
5-6: The creature can take either a bonus action or an action but may otherwise move, attack, or cast spells as normal.
7: The creature hurts itself in its confusion and takes 4d8 Psychic Damage and is then stunned until the start of its next turn.
8: The creature hurts itself in its confusion and takes 4d8 Psychic Damage but then can take its turn as normal.

Hopeless Maw. A creature hit by the Canticle of The Cave with any of its attacks must succeed on a DC 20 Strength Save or be Swallowed by the Canticle of The Cave. While Swallowed a creature cannot move, has disadvantage on attack rolls, and takes 3d10 acid damage at the start of each of its turns. The Canticle of The Cave may only Swallow up to three Creatures. If the Canticle takes 50 or more points of damage in a single round it regurgitates all swallowed creatures to a space 20ft away from it. Any creature which is knocked to 0 hit points while Swallowed is killed and dissolved in the Canticle's stomach acids.

Maw of Malediction. The Canticle of The Cave makes three Cavernous Maw attacks, one with each of its mouths or may make one Subterranean Sussurus attack.

• When the Canticle of The Cave becomes Mythic it makes up to four Cavernous Maw attacks and can substitute two attacks for a Subterranean Sussurus attack up to twice on its turn.

Cavernous Maw. Melee Weapon Attack: +8 to hit, reach 15 ft., 1 target. Hit: 15 (1d10 + 10) Piercing damage.

Subterranean Sussurus. Ranged Weapon Attack: DC 20 Strength Save, range 30ft cone. Hit: 20 (2d10 + 10) bludgeoning damage.

Fateful Dredge. As a reaction to taking damage the Canticle of The Cave can use its Maws to burrow under ground. The Maw bursts forth underneath the next enemy character to act at the beginning of that enemy's turn dealing 3d10 Bludgeoning damage.

Rage of the Dying Light. When the Canticle of The Cave loses its Temporary Hit Points it enters a Mythic Rage. While enraged in this way the Canticle gains an additional Maw of Malediction attack and the ability to use up to two Subterranean Sussurus attacks per turn. Additionally, the Canticle of The Cavern gains three Mythic Action points to spend on the options below which refresh on its turn each round. Finally, the Canticle of The Cavern gains Three Mythic Resistances which it can use to automatically succeed on a saving throw that it would otherwise have failed, when it saves in this way it takes no damage and suffers no ill effects from the spell or ability which triggered the save.

Fate Fueled Dredge (Costs 1 Action). The Canticle of The Cave uses its Fateful Dredge ability at the end of another creature's turn and appears at the start of the following creatures turn.

Voracious Vortex (Costs 2 Actions). The Canticle of The Cave targets up to three creatures within 40ft. Those creatures must make a DC 20 Constitution Save or have their life force sucked away by the Canticle of The Cave. On a failed save the targets take 2d10 Necrotic Damage, have their hit point maximum reduced by an equal amount, and are physically aged that number of years while the Canticle of The Cave regains a number of Temporary Hit Points equal to the damage dealt. Creatures take half damage on a save and suffer no other ill effects while the Canticle still regains the damage dealt in Temporary Hit Points.